In today's modern technology, phosphorus compounds play an increasingly important role. These compounds find utility as flame retardant additives for plastics and textiles, lubricant additives, biocides, herbicides, insecticides, pesticides, fungicides, growth regulators, ore flotation agents and metal plating additives.
Various classes of phosphorus derivative compounds are known.
U.S. Pat. No. 3,042,701 discloses phosphorus compounds having a plurality of pentavalent phosphorus ester radicals. The compounds disclosed in the above patent are selected from the class consisting of phosphate diesters and phosphate-containing polyesters. The pentavalent state is achieved by the oxidation or thionation of the phosphite-phosphonate intermediates to phosphate-phosphonates.
U.S. Pat. No. 2,372,244 discloses a process for the preparation of what the inventors believe to be "analogs of the alkylene glycol substituted partial esters of the acids of phosphorus".
U.S. Pat. No. 3,525,705 discloses a method for the production of fire resistant polyurethane products. In the method disclosed in the above patent, an organic polyisocyanate is reacted with the reaction product of the monoester of phosphoric acid, a mono or diester of diphosphoric acid, or a mono or diester of pyrophosphoric acid and an epoxide.
U.S. Pat. No. 2,909,559 discloses a process for producing hydroxyl-containing polymeric phosphate esters by heating a hydroxyl-containing phosphate ester of the structure: ##STR1## to a temperature of from about 90.degree. C. to about 250.degree. C.